When i have the sd card in my phone and connect it to the computer via charging cable it will only show internal not the sd card. I did a test and put a PDF in the sd card on my pc with the sd card adapter then put it in my phone and found it on my phone and is located at mnt/secure/staging I can put things in it but it won't show in es file explorer or regular file explorer. My device is rooted but i never had this problem with my other sd card. I upgraded from 16gb to 64 sandisk.